Drug eruptions with novel targeted therapies - immune checkpoint and EGFR inhibitors

Given the increasing use of novel targeted therapies, dermatologists are constantly confronted with novel cutaneous side effects of these agents. A rapid diagnosis and appropriate management of these side effects are crucial to prevent impairment of the patients' quality of life and interruptions of essential cancer treatments. Immune checkpoint and EGFR inhibitors are frequently used targeted therapies for various malignancies and are associated with a distinct spectrum of cutaneous adverse events. Exanthematous drug eruptions represent a particular diagnostic challenge in these patients. Immune checkpoint inhibitors can elicit a plethora of immune-related exanthemas, most commonly maculopapular, lichenoid, and psoriasiform eruptions. Additionally, autoimmune bullous dermatoses and exanthemas associated with connective tissue diseases may arise. In cases of severe, atypical or therapy-resistant presentations an extensive dermatological investigation including a skin biopsy is recommended. Topical and systemic steroids are the mainstay of treatment. Papulopustular eruptions represent the major cutaneous adverse effect of EGFR inhibitor therapy, occurring in up to 90 % of patients within the first two weeks of therapy, depending on the agent. Besides topical antibiotics and steroids, oral tetracyclines are the first choice in systemic treatment and can also be used as prophylaxis.

Erythema multiforme, Stevens-Johnson syndrome/toxic epidermal necrolysis - diagnosis and treatment

Prior to the first international consensus classification published in 1993, the clinical distinction between erythema multiforme (EM), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) had been subject to uncertainty and controversy for more than a century. Based on this classification, the three conditions are defined by the morphology of the individual lesions and their pattern of distribution. Etiopathogenetically, the majority of EM cases is caused by infections (primarily herpes simplex virus and Mycoplasma pneumoniae), whereas SJS/TEN are predominantly triggered by drugs. The SCORTEN (score of toxic epidermal necrolysis) can and should be used to assess disease prognosis in patients with SJS/TEN. While supportive treatment is generally considered sufficient for EM, there is still uncertainty as to the type of systemic therapy required for SJS/TEN. Given the lack of high-quality therapeutic trials and (in some cases) conflicting results, it is currently impossible to issue definitive recommendations for any given immunomodulatory therapy. While there is always a trade-off between rapid onset of treatment-induced immunosuppression and an uptick in infection risk, there has been increasing evidence that cyclosporine in particular may be able to halt disease progression (i.e. skin detachment) and lower mortality rates. Assistance in diagnosis and management of the aforementioned conditions may be obtained from the Center for the Documentation of Severe Skin Reactions (dZh) at the Department of Dermatology, University Medical Center, Freiburg, Germany.